Communication problems in computer networks can result in the loss of data, time and money. Such problems stem from a variety of sources. One major source of communication problems is faulty or malicious routing. Faulty routing occurs when a device in a computer network fails, due to a malfunction, to properly forward data packets to other devices in the computer network. On the other hand, malicious routing is when a device in a computer network intentionally fails to forward data packets.
Protocols do exist to facilitate routing in computer networks. For example, one of the protocols currently employed on the Internet to assist devices in properly routing data packets is the Border Gateway Protocol (BGP). However, BGP  includes no mechanism for verifying either the authenticity (the correct origin) or the accuracy of the routing information that it distributes. As a result, traffic on a network can be severely disrupted by routers announcing nonexistent routes, or simply failing to withdraw failed routes, as a result of either malfunction or malice. Two approaches have been suggested to solving this problem. One, Secure BGP (S-BGP), requires routing information to be digitally signed, so that routers advertising false routing information can be held accountable when detected. However, the overhead of a digital signature is large and possibly prohibitive, particularly when bringing a failed router back on line, at which time all routing advertisements for that router must be digitally signed at once. Furthermore, the management of the public-key infrastructure (PKI) that allows all routers to validate each other's digital signatures is a daunting task. Moreover, S-BGP does little to help detect or diagnose faulty routing information emanating (accidentally or maliciously) from a router; it only ensures reliable identification of the information's origin (for after-the-fact, out-of-band blame assignment).
Another proposed approach is to maintain a centralized registry of “plausibility” information about routing advertisements, so that blatantly invalid advertisements can be discounted when received. This approach can prevent the most egregious routing problems that arise from router misconfigurations, but it is still vulnerable to a wide range of both inadvertent and malicious false advertisements for routes that a particular router may be “entitled” to advertise, but cannot in fact serve. 